Escherichia coli probiotic exhibits in vitro growth-limiting effects on clinical feline uropathogenic E coli isolates.

OBJECTIVE: To characterize uropathogenic Escherichia coli (UPEC) in cases of clinical feline urinary tract infection (UTI) and subclinical bacteriuria and investigate the in vitro effects of E coli strain Nissle 1917 on isolate growth. ANIMALS: 40 cats with positive E coli culture results for urine collected during routine evaluation. PROCEDURES: Characterization of UPEC isolates was performed by PCR-based phylotype analysis and serotyping. Nissle 1917 effects on growth inhibition and competitive overgrowth against UPEC isolates were evaluated in vitro using a plate-based competition assay. RESULTS: Feline phylogroups were similar to previous human and feline UPEC studies, with most of the isolates belonging to phylogroup A (42.5%), B2 (37.5%), and D (15.0%). Fifty-two percent of isolates were found to be resistant to antimicrobials, with 19% of these being multidrug resistant (MDR). Nissle 1917 adversely affected the growth of 82.5% of all isolates and 100% of MDR isolates in vitro. The median zone of inhibition was 3.33 mm (range, 1.67 to 10.67 mm). Thirteen isolates were affected via competitive overgrowth and 20 via growth inhibition. CLINICAL RELEVANCE: UPEC isolates from cats were similar in phylogroup analysis to human and dog isolates. The in vitro effects of Nissle 1917 on UPEC warrant additional studies to determine if similar results can be duplicated in vivo.

Escherichia coli pathotype contamination in raw canine diets.

OBJECTIVE: To investigate the prevalence of Escherichia coli contamination and E coli virulence gene signatures consistent with known E coli pathotypes in commercially available conventional diets and raw-meat-based diets (RMBDs). SAMPLE: 40 diets in total (19 conventionally cooked kibble or canned diets and 21 RMBDs) obtained from retail stores or online distributors. PROCEDURES: Each diet was cultured for E coli contamination in 3 separate container locations using standard microbiological techniques. Further characterization of E coli isolates was performed by polymerase chain reaction-based pathotype and virulence gene analysis. RESULTS: Conventional diets were negative in all culture based testing. In RMBDs, bacterial contamination was similar to previous reports in the veterinary literature, with 66% (14/21) of the RMBDs having positive cultures for E coli. Among the 191 confirmed E coli isolates from these diets, 31.9% (61/191) were positive for virulence genes. Categorized by pathotype, isolates presumptively belonging to the neonatal meningitis E coli pathotype (15.7% [30/191]) were the most common, followed by enterohemorrhagic E coli (10.5% [20/191]), enteropathogenic E coli (5.8% [11/191]), uropathogenic E coli (2.1% [4/191]), and diffusely adherent E coli (1.6% [3/191]). CLINICAL RELEVANCE: The results of this study reaffirmed the bacteriologic risks previously associated with RMBDs. Furthermore, potential zoonotic concerns associated with identified pathotypes in these diets may have significant consequences for owners in the animals' home environment. Potential risk associated with bacterial contamination should be addressed in animals fed RMBDs.

Penile urethral resection and anastomosis augmentation with regional tissue tension relieving technique: A cadaveric mechanical study and clinical outcome in two dogs.

OBJECTIVE: To describe penile urethral augmentation anastomosis (PURAA) for resection anastomosis (RA) of the canine penile urethra by using autogenous tissue in two dogs and to determine the mechanical properties of the augmentation technique in cadaveric specimens. STUDY DESIGN: Cadaveric study and two case reports. ANIMALS: Sixteen canine cadavers and two dogs with urethral obstruction. METHODS: The lower urogenital system was harvested from cadavers and randomized into two groups: simple (S) and augmented (AUG) RA of the urethra. Tensile strength and peak load were compared between the two groups. Two dogs were treated with PURAA for urethral obstruction secondary to juxtaurethral neoplasms. RESULTS: Minimal tensile strength (MITS) and maximal tensile strength (MATS) were greater in the AUG group (MITS, 54.36 ± 24.0 N; MATS, 75.37 ± 34.79 N) compared with the S group (MITS, 11.78 ± 4.93 N, P = .0014; MATS, 13.74 ± 3.89 N, P = .0015). Both dogs recovered without complications. Histopathological examinations were consistent with a lipomatous mass in both cases. Both dogs had good medium-to-long-term outcomes. CONCLUSION: The augmentation technique improved the tensile properties of penile RA in normal cadavers and was associated with successful outcomes in two dogs. CLINICAL SIGNIFICANCE: Penile urethral augmentation anastomosis may help prevent stricture or leakage secondary to tension at the surgical site after penile urethral RA.

Defining Molecular Details of the Chemistry of Biofilm Formation by Raman Microspectroscopy.

Two protocols that allow for the comparison of Raman spectra of planktonic cells and biofilm formed from these cells in their growth phase have been developed. Planktonic cells are washed and flash-frozen in <1 min to reduce the time for metabolic changes during processing, prior to freeze-drying. Biofilm is formed by standing cells in 50 µL indentations in aluminum foil in an atmosphere of saturated water vapor for 24-48 h. The results for Escherichia coli type K12 cells, which do not readily form biofilm, are compared to those for Staphylococcus epidermidis cells, which prolifically synthesize biofilm. For E. coli, the Raman spectra of the planktonic and biofilm samples are similar with the exception that the spectral signature of RNA, present in planktonic cells, could not be detected in biofilm. For S. epidermidis, major changes occur upon biofilm formation. In addition to the absence of the RNA features, new bands occur near 950 cm-1 and between 1350 and 1420 cm-1 that are associated with an increase in carbohydrate content. Unlike the case in E. coli biofilm, the intensity of G base ring modes is reduced in but A and T base ring signatures become more prominent. For S. epidermis in the biofilm's amide III region, there is evidence of an increase in the level of ß-sheet structure accompanied by a decrease in α-helical content. The presence of biofilm is confirmed by microscope-aided photography and, separately, by staining with methyl violet.